The volume-outcome relation in the surgical treatment of esophageal cancer: a systematic review and meta-analysis.

This study was undertaken to conduct a systematic review and meta-analysis of the literature on the relation between procedural volume and outcome of esophagectomies. A systematic search was carried out to identify articles investigating effects of hospital or surgeon volume on short-term and long-term outcomes published between 1995 and 2010. Articles were scrutinized for methodological quality, and after inclusion of only high-quality studies, a meta-analysis assuming a random effects model was done to estimate the effect of higher volume on patient outcome. Heterogeneity in study results was evaluated with an I(2) -test and risk of publication bias with an Egger regression intercept. Forty-three studies were found. Sixteen studies met the strict inclusion criteria for the meta-analysis on hospital volume and postoperative mortality and 4 studies on hospital volume and survival. The pooled estimated effect size was significant for high-volume providers in the analysis of postoperative mortality (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.89-2.80) and in the survival analysis (OR, 1.17; 95% CI, 1.05-1.30). The meta-analysis of surgical volume and outcome showed no significant results. Studies in which the results were adjusted not only for patient characteristics but also for tumor characteristics and urgency of the operation showed a stronger correlation between hospital volume and mortality. Also, studies performed on data from the United States showed higher effect sizes. The evidence for hospital volume as an important determinant of outcome in esophageal cancer surgery is strong. Concentration of procedures in high-volume hospitals with a dedicated setting for the treatment of esophageal cancer might lead to an overall improvement in patient outcome.